Communality in microbial stress response and differential metabolic interactions revealed by time-series analysis of sponge symbionts.

The diversity and function of sponge-associated symbionts is now increasingly understood; however, we lack an understanding of how they dynamically behave to ensure holobiont stability in the face of environmental variation. Here, we performed a metatransciptomic analysis on three microbial symbionts of the sponge Cymbastela concentrica in situ over 14 months and through differential gene expression and correlation analysis to environmental variables uncovered differences that speak to their metabolic activities and level of symbiotic and environmental interactions. The nitrite-oxidizing Ca. Porinitrospira cymbastela maintained a seemingly stable metabolism, with the few differentially expressed genes related only to stress responses. The heterotrophic Ca. Porivivens multivorans displayed differential use of holobiont-derived compounds and respiration modes, while the ammonium-oxidizing archaeon Ca. Nitrosopumilus cymbastelus differentially expressed genes related to phosphate metabolism and symbiosis effectors. One striking similarity between the symbionts was their similar variation in expression of stress-related genes. Our time-series study showed that the microbial community of C. concentrica undertakes dynamic gene expression adjustments in response to the surroundings, tuned to deal with general stress and metabolic interactions between holobiont members. The success of these dynamic adjustments likely underpins the stability of the sponge holobiont and may provide resilience against environmental change.

On the way to specificity - Microbiome reflects sponge genetic cluster primarily in highly structured populations.

Most animals, including sponges (Porifera), have species-specific microbiomes. Which genetic or environmental factors play major roles structuring the microbial community at the intraspecific level in sponges is, however, largely unknown. In this study, we tested whether geographic location or genetic structure of conspecific sponges influences their microbial assembly. For that, we used three sponge species with different rates of gene flow, and collected samples along their entire distribution range (two from the Mediterranean and one from the Southern Ocean) yielding a total of 393 samples. These three sponge species have been previously analysed by microsatellites or single nucleotide polymorphisms, and here we investigate their microbiomes by amplicon sequencing of the microbial 16S rRNA gene. The sponge Petrosia ficiformis, with highly isolated populations (low gene flow), showed a stronger influence of the host genetic distance on the microbial composition than the spatial distance. Host-specificity was therefore detected at the genotypic level, with individuals belonging to the same host genetic cluster harbouring more similar microbiomes than distant ones. On the contrary, the microbiome of Ircinia fasciculata and Dendrilla antarctica - both with weak population structure (high gene flow) - seemed influenced by location rather than by host genetic distance. Our results suggest that in sponge species with high population structure, the host genetic cluster influence the microbial community more than the geographic location.

The Physcomitrella patens chromosome-scale assembly reveals moss genome structure and evolution.

The draft genome of the moss model, Physcomitrella patens, comprised approximately 2000 unordered scaffolds. In order to enable analyses of genome structure and evolution we generated a chromosome-scale genome assembly using genetic linkage as well as (end) sequencing of long DNA fragments. We find that 57% of the genome comprises transposable elements (TEs), some of which may be actively transposing during the life cycle. Unlike in flowering plant genomes, gene- and TE-rich regions show an overall even distribution along the chromosomes. However, the chromosomes are mono-centric with peaks of a class of Copia elements potentially coinciding with centromeres. Gene body methylation is evident in 5.7% of the protein-coding genes, typically coinciding with low GC and low expression. Some giant virus insertions are transcriptionally active and might protect gametes from viral infection via siRNA mediated silencing. Structure-based detection methods show that the genome evolved via two rounds of whole genome duplications (WGDs), apparently common in mosses but not in liverworts and hornworts. Several hundred genes are present in colinear regions conserved since the last common ancestor of plants. These syntenic regions are enriched for functions related to plant-specific cell growth and tissue organization. The P. patens genome lacks the TE-rich pericentromeric and gene-rich distal regions typical for most flowering plant genomes. More non-seed plant genomes are needed to unravel how plant genomes evolve, and to understand whether the P. patens genome structure is typical for mosses or bryophytes.

Delineation of ecologically distinct units of marine Bacteroidetes in the Northwestern Mediterranean Sea.

Bacteroidetes is one of the dominant phyla of ocean bacterioplankton, yet its diversity and population structure is poorly understood. To advance in the delineation of ecologically meaningful units within this group, we constructed near full-length 16S rRNA gene clone libraries from contrasting marine environments in the NW Mediterranean. Based on phylogeny and the associated ecological variables (depth and season), 24 different Bacteroidetes clades were delineated. By considering their relative abundance (from iTag amplicon sequencing studies), we described the distribution patterns of each of these clades, delimiting them as Ecologically Significant Taxonomic Units (ESTUs). Spatially, there was almost no overlap among ESTUs at different depths. In deep waters there was predominance of Owenweeksia, Leeuwenhoekiella, Muricauda-related genera, and some depth-associated ESTUs within the NS5 and NS2b marine clades. Seasonally, multi-annual dynamics of recurring ESTUs were present with dominance of some ESTUs within the NS4, NS5 and NS2b marine clades along most of the year, but with variable relative frequencies between months. A drastic change towards the predominance of Formosa-related ESTUs and one ESTU from the NS5 marine clade was typically present after the spring bloom. Even though there are no isolates available for these ESTUs to determine their physiology, correlation analyses identified the environmental preference of some of them. Overall, our results suggest that there is a high degree of niche specialisation within these closely related clades. This work constitutes a step forward in disentangling the ecology of marine Bacteroidetes, which are essential players in organic matter processing in the oceans.

Transposon Insertions, Structural Variations, and SNPs Contribute to the Evolution of the Melon Genome.

The availability of extensive databases of crop genome sequences should allow analysis of crop variability at an unprecedented scale, which should have an important impact in plant breeding. However, up to now the analysis of genetic variability at the whole-genome scale has been mainly restricted to single nucleotide polymorphisms (SNPs). This is a strong limitation as structural variation (SV) and transposon insertion polymorphisms are frequent in plant species and have had an important mutational role in crop domestication and breeding. Here, we present the first comprehensive analysis of melon genetic diversity, which includes a detailed analysis of SNPs, SV, and transposon insertion polymorphisms. The variability found among seven melon varieties representing the species diversity and including wild accessions and highly breed lines, is relatively high due in part to the marked divergence of some lineages. The diversity is distributed nonuniformly across the genome, being lower at the extremes of the chromosomes and higher in the pericentromeric regions, which is compatible with the effect of purifying selection and recombination forces over functional regions. Additionally, this variability is greatly reduced among elite varieties, probably due to selection during breeding. We have found some chromosomal regions showing a high differentiation of the elite varieties versus the rest, which could be considered as strongly selected candidate regions. Our data also suggest that transposons and SV may be at the origin of an important fraction of the variability in melon, which highlights the importance of analyzing all types of genetic variability to understand crop genome evolution.

Highly efficient gene tagging in the bryophyte Physcomitrella patens using the tobacco (Nicotiana tabacum) Tnt1 retrotransposon.

Because of its highly efficient homologous recombination, the moss Physcomitrella patens is a model organism particularly suited for reverse genetics, but this inherent characteristic limits forward genetic approaches. Here, we show that the tobacco (Nicotiana tabacum) retrotransposon Tnt1 efficiently transposes in P. patens, being the first retrotransposon from a vascular plant reported to transpose in a bryophyte. Tnt1 has a remarkable preference for insertion into genic regions, which makes it particularly suited for gene mutation. In order to stabilize Tnt1 insertions and make it easier to select for insertional mutants, we have developed a two-component system where a mini-Tnt1 with a retrotransposition selectable marker can only transpose when Tnt1 proteins are co-expressed from a separate expression unit. We present a new tool with which to produce insertional mutants in P. patens in a rapid and straightforward manner that complements the existing molecular and genetic toolkit for this model species.

Extensive amplification of the E2F transcription factor binding sites by transposons during evolution of Brassica species.

Transposable elements (TEs) are major players in genome evolution. The effects of their movement vary from gene knockouts to more subtle effects such as changes in gene expression. It has recently been shown that TEs may contain transcription factor binding sites (TFBSs), and it has been proposed that they may rewire new genes into existing transcriptional networks. However, little is known about the dynamics of this process and its effect on transcription factor binding. Here we show that TEs have extensively amplified the number of sequences that match the E2F TFBS during Brassica speciation, and, as a result, as many as 85% of the sequences that fit the E2F TFBS consensus are within TEs in some Brassica species. We show that these sequences found within TEs bind E2Fa in vivo, which indicates a direct effect of these TEs on E2F-mediated gene regulation. Our results suggest that the TEs located close to genes may directly participate in gene promoters, whereas those located far from genes may have an indirect effect by diluting the effective amount of E2F protein able to bind to its cognate promoters. These results illustrate an extreme case of the effect of TEs in TFBS evolution, and suggest a singular way by which they affect host genes by modulating essential transcriptional networks.

Validation of a new catalysed reporter deposition-fluorescence in situ hybridization probe for the accurate quantification of marine Bacteroidetes populations.

Catalysed reporter deposition-fluorescence in situ hybridization (CARD-FISH) is a powerful approach to quantify bacterial taxa. In this study, we compare the performance of the widely used Bacteroidetes CF319a probe with the new CF968 probe. In silico analyses and tests with isolates demonstrate that CF319a hybridizes with non-Bacteroidetes sequences from the Rhodobacteraceae and Alteromonadaceae families. We test the probes' accuracy in 37 globally distributed marine samples and over two consecutive years at the Blanes Bay Microbial Observatory (NW Mediterranean). We also compared the CARD-FISH data with the Bacteroidetes 16S rRNA gene sequences retrieved from 27 marine metagenomes from the TARA Oceans expedition. We find no significant differences in abundances between both approaches, although CF319a targeted some unspecific sequences and both probes displayed different abundances of specific Bacteroidetes phylotypes. Our results demonstrate that quantitative estimations by using both probes are significantly different in certain oceanographic regions (Mediterranean Sea, Red Sea and Arabian Sea) and that CF968 shows seasonality within marine Bacteroidetes, notably large differences between summer and winter that is overlooked by CF319a. We propose CF968 as an alternative to CF319a for targeting the whole Bacteroidetes phylum since it has better coverage, greater specificity and overall better quantifies marine Bacteroidetes.

Particle-association lifestyle is a phylogenetically conserved trait in bathypelagic prokaryotes.

The free-living (FL) and particle-attached (PA) marine microbial communities have repeatedly been proved to differ in their diversity and composition in the photic ocean and also recently in the bathypelagic ocean at a global scale. However, although high taxonomic ranks exhibit preferences for a PA or FL mode of life, it remains poorly understood whether two clear lifestyles do exist and how these are distributed across the prokaryotic phylogeny. We studied the FL (<0.8 µm) and PA (0.8-20 µm) prokaryotes at 30 stations distributed worldwide within the bathypelagic oceanic realm (2150-4000 m depth) using high-throughput sequencing of the small subunit ribosomal RNA gene (16S rRNA). A high proportion of the bathypelagic prokaryotes were mostly found either attached to particles or freely in the surrounding water but rarely in both types of environments. In particular, this trait was deeply conserved through their phylogeny, suggesting that the deep-ocean particles and the surrounding water constitute two highly distinct niches and that transitions from one to the other have been rare at an evolutionary timescale. As a consequence, PA and FL communities had clear alpha- and beta-diversity differences that exceeded the global-scale geographical variation. Our study organizes the bathypelagic prokaryotic diversity into a reasonable number of ecologically coherent taxa regarding their association with particles, a first step for understanding which are the microbes responsible for the processing of the dissolved and particulate pools of organic matter that have a very different biogeochemical role in the deep ocean.

High compositional and functional similarity in the microbiome of deep-sea sponges.

Sponges largely depend on their symbiotic microbes for their nutrition, health, and survival. This is especially true in high microbial abundance (HMA) sponges, where filtration is usually deprecated in favor of a larger association with prokaryotic symbionts. Sponge-microbiome association is substantially less understood for deep-sea sponges than for shallow water species. This is most unfortunate, since HMA sponges can form massive sponge grounds in the deep sea, where they dominate the ecosystems, driving their biogeochemical cycles. Here, we assess the microbial transcriptional profile of three different deep-sea HMA sponges in four locations of the Cantabrian Sea and compared them to shallow water HMA and LMA (low microbial abundance) sponge species. Our results reveal that the sponge microbiome has converged in a fundamental metabolic role for deep-sea sponges, independent of taxonomic relationships or geographic location, which is shared in broad terms with shallow HMA species. We also observed a large number of redundant microbial members performing the same functions, likely providing stability to the sponge inner ecosystem. A comparison between the community composition of our deep-sea sponges and another 39 species of HMA sponges from deep-sea and shallow habitats, belonging to the same taxonomic orders, suggested strong homogeneity in microbial composition (i.e. weak species-specificity) in deep sea species, which contrasts with that observed in shallow water counterparts. This convergence in microbiome composition and functionality underscores the adaptation to an extremely restrictive environment with the aim of exploiting the available resources.

Microbiome changes through the ontogeny of the marine sponge Crambe crambe.

BACKGROUND: Poriferans (sponges) are highly adaptable organisms that can thrive in diverse marine and freshwater environments due, in part, to their close associations with internal microbial communities. This sponge microbiome can be acquired from the surrounding environment (horizontal acquisition) or obtained from the parents during the reproductive process through a variety of mechanisms (vertical transfer), typically resulting in the presence of symbiotic microbes throughout all stages of sponge development. How and to what extent the different components of the microbiome are transferred to the developmental stages remain poorly understood. Here, we investigated the microbiome composition of a common, low-microbial-abundance, Atlantic-Mediterranean sponge, Crambe crambe, throughout its ontogeny, including adult individuals, brooded larvae, lecithotrophic free-swimming larvae, newly settled juveniles still lacking osculum, and juveniles with a functional osculum for filter feeding. RESULTS: Using 16S rRNA gene analysis, we detected distinct microbiome compositions in each ontogenetic stage, with variations in composition, relative abundance, and diversity of microbial species. However, a particular dominant symbiont, Candidatus Beroebacter blanensis, previously described as the main symbiont of C. crambe, consistently occurred throughout all stages, an omnipresence that suggests vertical transmission from parents to offspring. This symbiont fluctuated in relative abundance across developmental stages, with pronounced prevalence in lecithotrophic stages. A major shift in microbial composition occurred as new settlers completed osculum formation and acquired filter-feeding capacity. Candidatus Beroebacter blanensis decreased significatively at this point. Microbial diversity peaked in filter-feeding stages, contrasting with the lower diversity of lecithotrophic stages. Furthermore, individual specific transmission patterns were detected, with greater microbial similarity between larvae and their respective parents compared to non-parental conspecifics. CONCLUSIONS: These findings suggest a putative vertical transmission of the dominant symbiont, which could provide some metabolic advantage to non-filtering developmental stages of C. crambe. The increase in microbiome diversity with the onset of filter-feeding stages likely reflects enhanced interaction with environmental microbes, facilitating horizontal transmission. Conversely, lower microbiome diversity in lecithotrophic stages, prior to filter feeding, suggests incomplete symbiont transfer or potential symbiont digestion. This research provides novel information on the dynamics of the microbiome through sponge ontogeny, on the strategies for symbiont acquisition at each ontogenetic stage, and on the potential importance of symbionts during larval development.

Wild Fruits of Crataegus monogyna Jacq. and Sorbus aria (L.) Crantz: From Traditional Foods to Innovative Sources of Pigments and Antioxidant Ingredients for Food Products.

Hawthorn (Crataegus monogyna Jacq.) and whitebeam (Sorbus aria (L.) Crantz) are wild species traditionally used as ethnic foods in the Mediterranean area. Their red berries, and mainly the peels, may be used as ingredients due to their color (replacing other synthetic colorants) or functional properties. Some previous studies analyze all edible fruits, but there is very little literature on the composition and properties of the pulpless epidermis of the fruits of C. monogyna and no literature concerning the fruits of S. aria. Total phenolic compounds (TPC) and families of hydroxybenzoic acids, hydroxycinnamic acids, flavonols, and total monomeric anthocyanins were determined in the epidermis of C. monogyna and S. aria fruits. The in vitro antioxidant capacity was also determined using QUENCHER (Quick-Easy-New-CHEap-Reproducible) methodology. Anthocyanins profiles were analyzed in hydroalcoholic extracts through HPLC/MS. C. monogyna fruits presented higher content of TPC than S. aria, with hydroxybenzoic acids (2870.6 mg GAE/100g dw) as the major family, followed by flavonols (771.4 mg QE/100 g dw) and hydroxycinnamic acids (610.3 FAE/100 g dw). Anthocyanins were found in 251.7 mg cyanidin-3-glucoside/100 g dw, characterized by the content of cyanidin-O-hexoxide and peonidin-O-hexoxide. The levels of these compounds correlated with higher values of a* parameter (higher intensity of reddish color). These fruits also showed higher antioxidant capacity by Q-Folin-Ciocalteu and Q-FRAP. S. aria peels had fewer phenolic compounds, particularly anthocyanins (33.7 mg cyanidin-3-glucoside/100 g dw), containing different cyanidin derivatives. From these results, new insights about the composition of the epidermis of these wild fruits are provided, and their potential as ingredients for the food industry is corroborated.

Influence of the medical treatment schedule in new diagnoses patients with heart failure and reduced ejection fraction.

AIMS: Heart failure (HF) guidelines recommend treating all patients with HF and reduced ejection fraction (HFrEF) with quadruple therapy, although they do not establish how to start it. This study aimed to evaluate the implementation of these recommendations, analyzing the efficacy and safety of the different therapeutic schedules. METHODS AND RESULTS: Prospective, observational, and multicenter registry that evaluated the treatment initiated in patients with newly diagnosed HFrEF and its evolution at 3 months. Clinical and analytical data were collected, as well as adverse reactions and events during follow-up. Five hundred and thirty-three patients were included, selecting four hundred and ninety-seven, aged 65.5 ± 12.9 years (72% male). The most frequent etiologies were ischemic (25.5%) and idiopathic (21.1%), with a left ventricular ejection fraction of 28.7 ± 7.4%. Quadruple therapy was started in 314 (63.2%) patients, triple in 120 (24.1%), and double in 63 (12.7%). Follow-up was 112 days [IQI 91; 154], with 10 (2%) patients dying. At 3 months, 78.5% had quadruple therapy (p < 0.001). There were no differences in achieving maximum doses or reducing or withdrawing drugs (< 6%) depending on the starting scheme. Twenty-seven (5.7%) patients had any emergency room visits or admission for HF, less frequent in those with quadruple therapy (p = 0.02). CONCLUSION: It is possible to achieve quadruple therapy in patients with newly diagnosed HFrEF early. This strategy makes it possible to reduce admissions and visits to the emergency room for HF without associating a more significant reduction or withdrawal of drugs or significant difficulty in achieving the target doses.

Development and Validation of a Prediction Model and Score for Transthyretin Cardiac Amyloidosis Diagnosis: T-Amylo.

BACKGROUND: Although transthyretin cardiac amyloidosis (ATTR-CA) is often underdiagnosed, clinical suspicion is essential for early diagnosis. OBJECTIVES: The aim of this study was to develop and validate a feasible prediction model and score to facilitate the diagnosis of ATTR-CA. METHODS: This retrospective multicenter study enrolled consecutive patients who underwent 99mTc-DPD scintigraphy for suspected ATTR-CA. ATTR-CA was diagnosed if Grade 2 or 3 cardiac uptake was evidenced on 99mTc-DPD scintigraphy in the absence of a detectable monoclonal component or by demonstration of amyloid by biopsy. A prediction model for ATTR-CA diagnosis was developed in a derivation sample of 227 patients from 2 centers using multivariable logistic regression with clinical, electrocardiography, analytical, and transthoracic echocardiography variables. A simplified score was also created. Both of them were validated in an external cohort (n = 895) from 11 centers. RESULTS: The obtained prediction model combined age, gender, carpal tunnel syndrome, interventricular septum in diastole thickness, and low QRS interval voltages, with an area under the curve (AUC) of 0.92. The score had an AUC of 0.86. Both the T-Amylo prediction model and the score showed a good performance in the validation sample (ie, AUC: 0.84 and 0.82, respectively). They were tested in 3 clinical scenarios of the validation cohort: 1) hypertensive cardiomyopathy (n = 327); 2) severe aortic stenosis (n = 105); and 3) heart failure with preserved ejection fraction (n = 604), all with good diagnostic accuracy. CONCLUSIONS: The T-Amylo is a simple prediction model that improves the prediction of ATTR-CA diagnosis in patients with suspected ATTR-CA.

Evaluation of marine bacteroidetes-specific primers for microbial diversity and dynamics studies.

Assumptions on the matching specificity of group-specific bacterial primers may bias the interpretation of environmental microbial studies. As available sequence data continue growing, the performance of primers and probes needs to be reevaluated. Here, we present an evaluation of several commonly used and one newly designed Bacteroidetes-specific primer (CF418). First, we revised the in silico primer coverage and specificity with the current SILVA and RDP databases. We found minor differences with previous studies, which could be explained by the chosen databases, taxonomies, and matching criteria. We selected eight commonly used Bacteroidetes primers and tested them with a collection of assorted marine bacterial isolates. We also used the denaturing gradient gel electrophoresis (DGGE) approach in environmental samples to evaluate their ability to yield clear and diverse band patterns corresponding to Bacteroidetes phylotypes. Among the primers tested, CF968R did not provide satisfactory results in DGGE, although it exhibited the highest in silico coverage for Flavobacteria. Primers CFB560 and CFB555 presented undesirable features, such as requiring nested protocols or presence of degeneracies. Finally, the new primer CF418 and primer CF319a were used to explore the Bacteroidetes dynamics throughout a 1-year cycle in Mediterranean coastal waters (Blanes Bay Microbial Observatory). Both primers provided clear and diverse banding patterns, but the low specificity of CF319a was evidenced by 83.3 % of the bands sequenced corresponding to nontarget taxa. The satisfactory DGGE banding patterns and the wide diversity of sequences retrieved from DGGE bands with primer CF418 prove it to be a valuable alternative for the study of Bacteroidetes communities, recovering a wide range of phylotypes within the group.

Heart Transplantation in Systemic Sclerosis: A Therapeutic Option. Presentation of a Case and Literature Review.

Cardiac involvement in systemic sclerosis (SSc) is rare but leads to poor short-term prognosis. Evidence regarding heart transplantation (HT) is scarce and is based on experience with isolated cases. We present this case with the aim of analysing the characteristics of a patient with SS who has undergone a successful transplant.

Activation of PPARγ and δ by dietary punicic acid ameliorates intestinal inflammation in mice.

The goal of the present study was to elucidate the mechanisms of immunoregulation by which dietary punicic acid (PUA) prevents or ameliorates experimental inflammatory bowel disease (IBD). The expression of PPARγ and δ, their responsive genes and pro-inflammatory cytokines was assayed in the colonic mucosa. Immune cell-specific PPARγ null, PPARδ knockout and wild-type mice were treated with PUA and challenged with 2·5 % dextran sodium sulphate (DSS). The prophylactic efficacy of PUA was examined in an IL-10(-/-) model of IBD. The effect of PUA on the regulatory T-cell (Treg) compartment was also examined in mice with experimental IBD. PUA ameliorated spontaneous pan-enteritis in IL-10(-/-) mice and DSS colitis, up-regulated Foxp3 expression in Treg and suppressed TNF-α, but the loss of functional PPARγ or δ impaired these anti-inflammatory effects. At the cellular level, the macrophage-specific deletion of PPARγ caused a complete abrogation of the protective effect of PUA, whereas the deletion of PPARδ or intestinal epithelial cell-specific PPARγ decreased its anti-inflammatory efficacy. We provide in vivo molecular evidence demonstrating that PUA ameliorates experimental IBD by regulating macrophage and T-cell function through PPARγ- and δ-dependent mechanisms.

Heart Transplantation in Systemic Sclerosis: A Therapeutic Option. Presentation of a Case and Literature Review.

Cardiac involvement in systemic sclerosis (SSc) is rare but leads to poor short-term prognosis. Evidence regarding heart transplantation (HT) is scarce and is based on experience with isolated cases. We present this case with the aim of analysing the characteristics of a patient with SS who has undergone a successful transplant.

Stress response of the marine sponge Scopalina sp.. Can microbial community composition predict sponge disease?

Disease has become an increasingly recognised problem in the marine environment, but our understanding of the factors that drive disease or our ability to predict its occurrence is limited. Marine sponges are known for their close associations with microorganisms, which are generally accepted to underpin sponge health and function. The aim of this study is to explore whether the microbial community composition of sponges can act as a predictor of disease occurrence under stressful environmental conditions. The development of a naturally occurring disease in the temperate sponge species Scopalina sp. was reproducibly recreated in a flow-through aquarium environment using increasing temperature stress. Throughout the experiments, four morphological health states were observed and described. Fingerprinting based on terminal restriction fragment length polymorphism of the bacterial community uncovered a statistically significant signature in healthy sponges prior to stress or apparent symptoms that correlated with the time it took for the disease to occur. This shows that the bacterial community composition of individual sponges can act as predictors of necrotic disease development. To the best of our knowledge, this is the first time a microbial signature of this nature has been reported in marine sponges and this finding can contribute to unravelling cause-effect pathways for stress-related dysbiosis and disease.